Women’s Health

Hello and welcome to Nutrition Facts – the podcast that brings you the latest in evidence-based nutrition research.  I’m your host Dr. Michael Greger.

I’m often asked what my opinion is about one food or another.  I know what people are asking but, you know, I’m not interested in opinions.  I’m not interested in beliefs.  I’m interested in the science.  What does the best available balance of evidence published in the peer-reviewed medical literature show right now?  That’s why I wrote my book, “How Not to Die”, and why I created my nonprofit site NutritionFacts.org and, now, this podcast.

Today we’re going to discuss women’s health.  We’re going to dive into four very different topics that affect the quality of life for women of all ages.  First up is a look at the optimal diet if you’re diagnosed with breast cancer.  Next, we’ll examine how long to detox from fish before pregnancy.  Then, it’s the safety of calcium supplements and, finally, we’ll look at a dietary remedy for painful periods.

So let’s start with some new research on diet and breast cancer. 

A half-million Americans are expected to die this year from cancer, equal to five jumbo jets crashing every day.  The number of Americans who die from cancer each year is more than all those who have died in all U.S. wars combined and this happens every single year.

After a cancer diagnosis, people tend to clean up their diets.  About a third to a half of breast cancer patients, for example, make healthy dietary changes following diagnosis, such as increasing fruit and vegetable consumption, decreasing meat, fat, and sugar intakes. Does this actually help that late in the game?  Well, the Women’s Healthy Eating and Living Study was undertaken in a few thousand breast cancer survivors to determine if a plant-based, low-fat, high-fiber diet could influence breast cancer recurrence rates and survival.

Previously, they famously reported that simple changes, five or more servings of fruits and veggies a day, and just, like, walking thirty minutes a day, six days a week, was associated with a significant survival advantage, cutting risk nearly in half.  Note, I said fruits and veggies, and exercise.  Here’s the proportion of women with breast cancer surviving nine years in the study, if they had low fruit and vegetable consumption and low physical activity or high in one and low in the other, but here’s the survival curve of those high in both and it worked just as well in women with estrogen-receptor-negative tumors, which normally have twice the mortality, unless you eat a few fruits and veggies and take a few strolls.  The high should really be in quotes.  I mean, you could eat five servings in a single meal and certainly walk more than, like, two miles a day.

Imagine, for a second, you have been diagnosed with breast cancer.  Imagine sitting in that chair in the doctor’s office as your doctor gives you the news but there’s a new experimental treatment that can cut your chances of dying in the next few years from like 16% down to just 4%.  To quadruple their survival rate, many women would remortgage their homes to fly to some quack clinic in Mexico, would lose all their hair to chemo but, most, apparently, couldn’t stand the thought of eating broccoli and, indeed, that’s what the latest report from the Women’s Healthy Eating and Living Study found:  Fruits and vegetables may be good, but cruciferous vegetables may be better. For women on tamoxifen, for example, if one of their five daily servings of fruits and veggies was broccoli, or cauliflower, collards, cabbage, or kale, the risk of cancer recurrence may be cut in half.

This next story features some new information on the risks of eating fish if you’re even considering getting pregnant.  Increased fish consumption of mothers before and during pregnancy leads to increased exposure to both mercury and the long-chain omega-3, DHA.  Mercury may negatively affect brain development in one’s unborn baby, whereas DHA may stimulate brain development.  Unfortunately, in the last two national surveys of women of childbearing age, they were less aware and knowledgeable about this problem than other women, despite FDA and EPA campaigns to inform every OB/GYN and pediatrician in the United States about the potential risks of mercury in fish.  But I wanted to highlight the before, not just during pregnancy, but even before one gets pregnant.

Since mercury sticks around, women may want to avoid polluted fish consumption for a year before they get pregnant in addition to just during pregnancy.  The reason they suggest a year before getting pregnant is because the half-life of mercury in the body is estimated to be about two months.  They fed folks two servings a week of tuna and other high-mercury fish to push their mercury levels up and then stopped the fish at week 14 and, slowly but surely, their levels came back down.  I know a lot of moms are concerned about exposing their children to mercury-containing vaccines, but if they just ate a single serving a week or less of fish during pregnancy, the latest data shows their infants end up with substantially more mercury in their bodies than getting injected with up to six mercury-containing vaccines.

But, with a two-month half-life, within a year of stopping fish consumption, your body can detox nearly 99% of the mercury. Unfortunately, the other industrial pollutants in fish can take longer for our body to get rid of–a half-life as long as ten years for certain dioxins, and PBCs, and DDT metabolites found in fish.  So, to get that same 99% drop could take 120 years, which is a long time to delay one’s first child.

What do these other pollutants do?  Well, high concentrations of industrial contaminants associated with 38 times the odds of diabetes.  That’s as strong as the relationship between smoking and lung cancer.  Isn’t diabetes mostly about obesity, though?  Well, these are fat-soluble pollutants and, so, as people get fatter, the retention and toxicity of persistent organic pollutants related to the risk of diabetes may increase, suggesting the shocking possibility that obesity may only be a vehicle for such chemicals.  We may be storing pollutants in our spare tire, like a hazardous waste dump.

Now, the pollutants could just be a marker of animal product consumption.  Maybe that’s why there’s such higher diabetes risk, since more than 90% of the persistent organic pollutants comes from animal foods, unless you work in a chemical factory, or stumble across some toxic waste and, indeed, in the U.S., every serving of fish a week is associated with a 5% increased risk of diabetes, which makes fish consumption about 80% worse than red meat.

Next up:  Calcium supplements.  Should women take them?  Are they safe?  We would naturally get lot of our calcium from eating dark green leafy vegetables, not from eating Tums.  As always, let’s see what the science says.

In 12 short years, government panels have gone from suggesting widespread calcium supplementation may be necessary to protect our bones to do not supplement.  What happened?  It all started with a 2008 study in New Zealand.  Short-term studies had shown that calcium supplementation may drop blood pressures by about a point.  Though the effect appears transient, disappearing after a few months, but better than nothing, and excess calcium in the gut can cause fat malabsorption, by forming soap fat, reducing saturated fat absorption and increasing fecal saturated fat content and, indeed, if you take a couple Tums along with your half bucket of KFC, up to twice as much fat could end up in your stool, and with less saturated fat absorbed into your system, your cholesterol might drop.  So, the New Zealand researchers were expecting to lower heart attack rates by giving women calcium supplements.  To their surprise, there appeared to be more heart attacks in the calcium supplement group.

Was this just a fluke?  All eyes turned to the Women’s Health Initiative, the largest and longest randomized controlled trial of calcium supplementation.  The name might sound familiar.  That’s the study that uncovered how dangerous hormone replacement therapy was.  Would it do the same for calcium supplements?  The Women’s Health Initiative reported no adverse effects; however, the majority of participants were already taking calcium supplements before the study started.  So, effectively, the study was just comparing higher versus lower-dose calcium supplementation, not calcium supplements versus no calcium supplements.  But what if you go back and just see what happened to the women who started out not taking supplements and then were randomized to the supplement group?  Those who started calcium supplements suffered significantly more heart attacks or strokes.  Thus, high dose or low dose, any calcium supplementation seems to increase cardiovascular disease risk.

So, researchers went back, digging through other trial data for heart attack and stroke rates in women randomized to calcium supplements, with or without vitamin D added, and confirmed the danger and most of the population studies agreed, users of calcium supplements tended to have increased rates of heart disease, stroke, and death.

The supplement industry was not happy, accusing the researchers of relying, in part, on self-reported data, like they just ask people if they had a heart attack or not rather than verifying it and, indeed, long-term calcium supplementation causes all sorts of gastrointestinal distress including twice the risk of being hospitalized with acute symptoms that may have been confused with a heart attack but, no, the increased risk was seen consistently across the trials whether the heart attacks were verified or not.

Okay, but why do calcium supplements increase heart attack risk but not calcium you get in your diet?  Perhaps because when you take calcium pills, you get a spike of calcium in your bloodstream that you don’t get just eating calcium-rich foods.  Within hours of taking supplemental calcium, the calcium levels in the blood shoot up and can stay up as long as eight hours.  This evidently produces what’s called a hypercoagulable state, your blood clots more easily, which could increase the risk of clots in the heart and brain and, indeed, higher calcium blood levels are tied to higher heart attack and stroke rates.  So, the mechanism may be calcium supplements leading to unnaturally large, rapid, and sustained calcium levels in the blood, which can have a variety of potentially problematic effects.

Calcium supplements have been widely embraced on the grounds that they are a natural and, therefore, a safe way, of preventing osteoporotic fractures but, it is now becoming clear that taking calcium in one or two daily doses is not natural, in that it does not reproduce the same metabolic effects as calcium in food, the way nature intended, and, furthermore, the evidence is also becoming steadily stronger that calcium supplementation may not be safe.  That’s why most organizations providing advice regarding bone health now recommend that individuals should obtain their calcium requirement from diet in preference to supplements.

Finally, it’s painful menstrual periods and what to do about them. 

Dysmenorrhea is the medical term for painful, crampy periods.  It affects almost half of menstruating women.  Yet, despite the substantial effect on quality of life and general wellbeing, few women will seek treatment, as they believe it will not help.

There are treatments available, though.  Modern medicine to the rescue!  There are surgical options, such as neuroablation, where surgeons go in, attempting to cut or destroy the nerves leading to the uterus, or doctors can just take out your uterus completely, though there are certainly a bunch of hormones in pills and shots that can suppress the menstrual cycle altogether.

Since the pain is caused by inflammation, anti-inflammatory drugs, like ibuprofen, are the most commonly used, achieving symptomatic relief in about two-thirds of women.  These drugs are effective, though women using them need to be aware of the significant risk of adverse drug side effects.

Though there are a bunch of non-drug, non-surgical treatments, like acupuncture, the evidence for the effectiveness of these treatments is generally weak.

One of the latest advances in treatment involves the use of a single high dose of vitamin D.  A randomized, double-blind, placebo-controlled study, the placebo did nothing; in fact, most women got worse but, the women who got the vitamin D all felt better.

But, wait a second; if it’s pain caused by inflammation, how about putting women on an anti-inflammatory diet?  Thirty-three women suffering from painful periods were placed on a vegan diet for two cycles and experienced significant reductions in menstrual pain duration, from four days down to three days, and a significant reduction in pain intensity, as well as an improvement in symptoms of PMS, like bloating.

This was a crossover study, so after two months eating vegan, the women were supposed to go back to their regular diets to see if the pain would return but, the women felt so much better that when the researchers said okay, now we need you to go back to your regular diet to test before and after, several said, no way José, and refused, even though they were required to by the study protocol.

Doctors too often patronizingly think that patients simply won’t adhere to therapeutic diets but, when they surveyed these women during the study, not only did they have fewer cramps, but they were losing weight, reported, you know, increased energy, better digestion, better sleep.

This showed that you don’t have to be in some Ornish or Esselstyn study facing certain death after a heart attack to stick to a plant-based diet.  It’s well accepted by people, even when testing more benign conditions.

Thanks for listening to this episode of Nutrition Facts.  To see any graphs, charts, graphics, images, or studies mentioned here, please go to the Nutrition Facts podcast landing page.  There, you’ll find all the videos I highlighted with links to all the sources cited.

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Thanks for listening to Nutrition Facts.  I’m Dr. Michael Greger.